Support Assembly for a Wheel End Reduction Drive

This application claims priority to German Utility Model Application No. 20 2024 101 583.5, entitled “SUPPORT ASSEMBLY FOR A WHEEL END REDUCTION DRIVE”, filed Apr. 1, 2024. The entire contents of the above-identified application is hereby incorporated by reference for all purposes.

The present disclosure relates to a support assembly for a wheel end reduction drive, to an axle assembly comprising said support assembly, and to an electric vehicle.

In many automotive vehicles, for example in electric vehicles, the drive shafts are coupled to the drive wheels via wheel end reduction drives which reduce a high rotational speed of the drive shafts to a lower rotational speed of the drive wheels. Often, a wheel end reduction drive includes an epicyclic or planet gear train. An epicyclic gear train typically includes a sun gear, a ring gear, a planetary carrier, and planet gears rotatably mounted on the planetary carrier, wherein the planet gears are drivingly engaged with or in mesh with the sun gear and with the ring gear. Epicyclic gear trains are commonplace in wheel end reduction drives due to their high degree of compactness.

A support assembly for supporting one or more of the sun gear, the ring gear and the planetary carrier of the epicyclic wheel end reduction drive usually includes an axle member, for example an axle housing or a steering knuckle, and a support member mounted on the axle member. Typically, the support member is mounted on the axle member via fastening members such as bolts. One of the sun gear, the ring gear and the planetary carrier of the epicyclic wheel end reduction drive may then be fixedly connected to or fixedly mounted on the support member.

In order to enhance the stability and longevity of the support assembly, the axle member and the support member may further be connected to one another via a splined connection. For example, the axle member may include a tube-like female section comprising a cylindrical inner surface having a plurality of radially inward facing splines formed therein.

And the support member may include a male section comprising a cylindrical outer surface having a plurality of radially outwardly facing splines formed therein. The male section of the support member is then typically received in the tube-like female section of the axle member, wherein the splines of the axle member and the splines of the support member engage one another to form a torque-proof connection between the axle member and the support member.

However, machining a splined connection between the axle member and the support member as described above usually requires a high degree of precision and dedicated, expensive tools. Consequently, the production of a support assembly of the above-described type may be labor-intensive and costly.

Thus, there is demand for a support assembly for an epicyclic wheel end reduction drive with an alternative torque-proof connection between an axle member and a support member which can be produced preferably easily and at preferably low cost.

This demand is met by a support assembly for an epicyclic wheel end reduction drive as described herein, by an axle assembly including said support assembly, and by an electric vehicle including said axle assembly.

The presently proposed support assembly for a wheel end reduction drive comprises an axle member, a support member, and a plurality of bolts extending in an axial direction and connecting the support member to the axle member. An axial end face of at least one of the axle member and the support member forms axially protruding tooth members, and an axial end face of at least the other of the axle member and the support member forms axially extending recesses. The axially protruding tooth members are received in the axially extending recesses, thereby forming a torque-proof connection between the axle member and the support member with respect to a rotation axis parallel to the axial direction.

Typically, the torque-proof connection between the axle member and the support member including the axially protruding tooth members received in the axially extending recesses can be manufactured more easily and at lower cost with respect to known support assemblies for wheel end reduction drives.

The axially protruding tooth members may be formed in one piece with the one of the axle member and the support member. For example, some or all of the axially protruding tooth members may be formed in one piece with the axle member. Additionally or alternatively, some or all of the axially protruding tooth members may be formed in one piece with the support member. Alternatively, it is conceivable that some or all of the tooth members are formed as separate pieces which are connected to the axial end face of either one or both of the axle member and the support member, for example via fastening members such as bolts. The tooth members and the recesses may be arranged symmetrically with respect to the rotation axis.

At least one of the plurality of bolts connecting the support member to the axle member may extend through one or more of the axially protruding tooth members.

The axle member and the support member may each feature an axially extending through hole aligned with the rotation axis and configured to receive a drive shaft therethrough. For instance, the axle member may comprise a tube-like spindle configured to support a wheel hub. The tube-like spindle may then feature an axially extending through hole as described above.

One or more contact faces of the tooth members configured to transmit and/or absorb torque between the support member and the axle member may extend in parallel to the axial direction. For example, the rotation axis may lie in a plane with one or more of the contact faces of the tooth members. In this way, the contact faces of the tooth members may efficiently transmit and/or absorb torque between the axle member and the support member.

The support member may be a ring gear carrier. Or in other words, the support member may be configured to be fixedly connected to a ring gear of the epicyclic wheel end reduction drive. The ring gear carrier may then be a gear-like member having a circular rim with radially outward facing teeth formed therein, for example. The radially outward facing teeth of the ring gear carrier may then be engaged with corresponding radially inward facing teeth of the ring gear, for example to provide a torque-proof connection between the ring gear carrier and the ring gear. However, it is likewise conceivable that in some embodiments the support member supports a planetary carrier of an epicyclic wheel end reduction drive. That is, in some embodiments the support member may be configured to be fixedly connected to a planetary carrier of an epicyclic wheel end reduction drive.

The axle member may be a steering knuckle. However, it is likewise conceivable that the axle member is or includes an axle housing, for example.

The presently proposed axle assembly comprises the previously described support assembly and an epicyclic wheel end reduction drive supported on the support assembly. For example, the epicyclic wheel end reduction drive may include an outer ring gear mounted on the support member. The outer ring gear may have a symmetry axis aligned with the rotation axis. The outer ring gear may comprise a plurality of radially inward facing teeth.

The axle assembly may further comprise a wheel hub rotatably supported on the axle member, and a drive shaft. The drive shaft may be coupled to the wheel hub via the epicyclic wheel end reduction drive. The epicyclic wheel end reduction drive may further include a sun gear which may be fixedly mounted on the drive shaft. Also, the epicyclic wheel end reduction drive may include a planetary carrier, and a plurality of planet gears rotatably mounted on the planetary carrier. The planetary carrier may be fixedly mounted on or fixedly connected to the wheel hub, for example. The planet gears may mesh with the sun gear and with the outer ring gear.

The presently proposed electric vehicle comprises an electric motor and the above-mentioned axle assembly. The electric motor may be drivingly engaged or drivingly engageable with the epicyclic wheel end reduction drive.

Embodiments of the presently proposed support assembly, axle assembly and electric vehicle are depicted in the accompanying drawing and are described in the following detailed description. It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

illustrates a perspective view of a support assemblyof the presently proposed type according to a first embodiment. The support assemblyis configured to support a wheel end reduction drive for an automotive vehicle, for example an epicyclic wheel end reduction drive. The support assembly comprises an axle member, a support member, and a plurality of boltsconnecting the support memberto the axle member.further illustrates a wheel hubwhich is rotatably mounted on the axle memberand configured to rotate with respect to a rotation axis. The boltsconnecting the support memberto the axle memberextend in parallel to the rotation axis. In the embodiment depicted here, there is a total of six boltsconnecting the support memberto the axle member. The boltsare arranged symmetrically with respect to the rotation axis. Only for illustrative purposes, not all of the bolts connecting the support memberto the axle memberare designated with reference signs. The axle memberand the support memberare stationary with respect to the rotation axis. Or in other words, the axle memberand the support memberare not configured to rotate with respect to the rotation axis.

In the embodiment depicted inthe axle memberis a steering knuckle which, when mounted on a vehicle, is rotatable relative to a stationary vehicle chassis with respect to a steering axis. However, it is understood that in other embodiments not explicitly depicted here, the axle membermay include an axle housing, for example, which may be stationary with respect to a vehicle chassis. In the illustrated embodiment the support memberhas an axially flat and laterally circular, disc-like or gear-like shape. Further, a circular outer rim of the support memberhas a plurality radially outward facing gear teethas will be further explained with respect tobelow. It is understood that in alternative embodiments a size and/or shape of the support membermay differ from the size and/or shape depicted in the figures and explicitly described herein.

shows a sectional view of a detail of the support assemblyofwherein the sectional plane includes the rotation axis. Here and in all of the following, features recurring in different figures are designated with the same reference signs. The axle memberand the support memberfeature axially extending through holes,respectively, which are aligned with the rotation axis. The through holes,each have a cylindrical shape and are arranged symmetrically with respect to the rotation axis. As will be described with respect to, the axially extending through holes,are configured to receive a drive shaft passing therethrough. The detail of the axle membershown informs a tube-like spindle portion lf. The spindle portion If forms an axial end portion of the axle assemblyfacing the support member. The wheel hubis rotatably mounted on the spindle portionby means of a bearing, for example a roller bearing. The boltsconnecting the support memberto the axle memberextend through axially extending boringsformed in the support memberand are received in corresponding axially extending borings Ic formed in the axle member. For example, the boltsmay have male threads which may be engaged with corresponding female threads formed in the borings

andfeature perspective views of the axle memberand of the support memberof the support assemblyof, respectively. As can be seen in, an axial end face of the axle memberfacing the support member, or, more specifically, an axial end face of the spindle portionof the axle member I facing the support member, has been machined to form two recesses or cutoutsIn a circumferential direction, these recesses or cutoutsform two axially protruding tooth membersin the axial end face of the axle memberfacing the support member, wherein the tooth membersare disposed in between the recesses or cutoutsThe recesses or cutoutsand the tooth membersare arranged symmetrically with respect to the rotation axis. In a lateral plane perpendicular to the rotation axis, both the two recesses or cutoutsand the two tooth members la are disposed diametrically opposite to one another, respectively. More specifically, in a lateral plane perpendicular to the rotation axisthe axially extending recesses or cutoutshave the shape of an intersection between the walls of the tubular spindle portion If with a sector of a circle whose centerpoint coincides with the rotation axis.

In the embodiment depicted here, in a circumferential direction perpendicular to the rotation axiseach of the recesses or cutoutsspans a circular sector of 60 degrees, while each of the tooth membersformed in between the recesses or cutoutsspans a circular sector of 120 degrees. Here, an axial depth of the recesses or cutoutscorresponds approximately to a radial thickness of the walls of the tubular spindle portionof the axle member. An axial height of the tooth members la is given by the axial depth of the recesses or cutoutsformed therebetween. It is understood that in alternative embodiments the numbers of the recesses or cutoutsand of the tooth membersmay be smaller or larger than two, and/or that in alternative embodiments the recesses or cutoutsand/or the tooth members la formed therebetween may have different shapes and/or different sizes or extensions.further illustrates that some of the axially extending borings Ic extend from the recesses or cutoutsfor receiving the bolts, while others of the axially extending borings Ic extend through the tooth members la for receiving the bolts

illustrates that an axial end face of the support memberfacing the axle memberforms two axially protruding tooth membersThe tooth membersare sized and shaped to be received in the recesses or cutoutsformed in the axle memberin a form fit or positive fit, here in both the circumferential direction perpendicular to the rotation axisand in an axial direction parallel to the rotation axis. In other words, a lateral or circumferential size and/or shape of the tooth membersof the support membercorresponds with a lateral or circumferential size and/or shape of the recesses or cutoutsof the axle member. And an axial height of the tooth membersof the support membermay correspond to the axial depth of the recesses or cutoutsformed in the axle member. In this way, when the tooth membersof the support memberare received or fully received in the recesses or cutoutsof the axle member, the tooth membersof the axle memberand the tooth membersof the support memberengage one another in a form fit, thereby providing a torque-proof connection or an additional torque-proof connection between the axle memberand the support memberwith respect to the rotation axis.

In the illustrated embodiment, the support memberand the tooth membersaxially protruding therefrom are made in one piece. However, it is understood that in alternative embodiments not explicitly depicted here, the support memberand the tooth membersmay possibly be formed or made as separate pieces which are connected to one another, such as through bolts or rivets, by welding, or the like.further illustrates that the axially extending through boringsformed in the support memberfor receiving the boltsextend both through the tooth membersand through areas disposed in between the tooth membersin a circumferential direction perpendicular to the rotation axis.

The tooth membersof the axle memberhave axially extending contact faces. Similarly, the tooth membersof the support memberhave axially extending contact faces. When the tooth membersof the support memberare received or fully received in the recesses or cutoutsof the axle memberand the tooth members,are engaged with one another to provide a torque-proof connection between the support memberand the axle memberwith respect to the rotation axis, the tooth members,abut one another along the contact faces,so that torque may be transmitted or absorbed between the support memberand the axle membervia the contact facesIn the embodiment depicted here, each of the contact facesextends in parallel to the rotation axis. More specifically, each of the contact faceslies in a plane which includes the rotation axis.

The axial cross section ofshows one of the tooth membersof the support memberreceived in one of the recesses or cutoutsformed in the axial end face of the spindle portionof the axle memberin a form fit. The tooth membersof the support memberare engaged with the tooth membersof the axle memberto provide a torque-proof connection between the support memberand the axle memberwith respect to the rotation axis. The axially extending boltsconnect the support memberto the axle memberin the axial direction parallel to the rotation axis. As can be seen in, a boltextends through the tooth memberof the support member, and boltsextend through tooth members la of the axle member.shows a perspective view of this arrangement.

anddepict the axial end face of the spindle portion If of the axle memberaccording to a slight variation of the embodiment illustrated in the previous figures. The embodiment shown indiffers from the embodiment shown in the previous figures in that inthe recesses or cutoutsformed in the axial end face of the spindle portiondo not extend all the way through the tubular walls of the spindle portion If in a radial direction perpendicular to the rotation axis. Rather, ina radially outer surface of an axial end portion of the spindle portionfacing the support memberhas an entirely cylindrical shape. In this way, the radially outer surface of the spindle portionmay provide additional support for the bearing, for example (see).

show the axle memberand the support memberof a support assemblyof the presently proposed type according to a second embodiment. As before, recurring features are designated with the same reference signs. For simplicity, only those features which distinguish the support assemblyoffrom the support assemblyillustrated in the previous figures will be explained in some detail. If not explicitly mentioned otherwise, the support assemblymay include the same features as the support assembly.

In contrast to the support assemblyof the previous figures, in the support assemblyofthe support memberincludes two additional recessesThe recessesare configured as through holes extending through the support memberin the axial direction parallel to the rotation axis. The recessesare arranged, sized and shaped to receive the axially protruding tooth membersof the axle memberin a form fit. In other words, the recessesare shaped as sections of a ring whose center point coincides with the rotation axis. Like the tooth membersof the axle member, the two recessesformed in the support memberare arranged symmetrically with respect to the rotation axisand are disposed diametrically opposed to one another with respect to the rotation axis. The recessesare disposed at a distance from the axially extending central cylindrical through holeformed in the support member. And further in contrast to the support assemblyof the previous figures, in the support assemblyofall of the axially extending through borings Ic formed in the axial end face of the spindle portion If of the axle memberfor receiving the boltsextend from the recesses or cutoutsformed in between the tooth members

Like in the support assemblyillustrated in the previous figures, when, in the support assemblyof, the tooth members la of the axle memberare received or fully received in the recessesformed in the support member, the support memberand the axle memberengage one another in a form fit or positive fit. This form fit or positive fit between the support memberand the axle memberforms a torque-proof connection or an additional torque-proof connection between the support memberand the axle memberwith respect to the rotation axis.

shows a sectional view of an axle assemblyof the presently proposed type, wherein the sectional plane includes the rotation axis. As before, recurring features are designated with the same reference signs. The axle assemblyincludes the support assemblydepicted in, the wheel hubmounted on the spindle portionof the axle membervia the bearing, a drive shaft, and an epicyclic wheel end reduction drivecoupling the drive shaftto the wheel hub, thereby allowing the drive shaftto drive a wheel mounted on the wheel hub, for example via a hub flangemounted on the wheel hub. It is understood that in alternative embodiments not explicitly depicted here, the axle assemblymay alternatively include the support assemblyaccording to the variation depicted in, or the support assemblyaccording to. The drive shaftincludes a first drive shaft portionand a second drive shaft portionconnected to one another through a double universal joint (DUJ)The second drive shaft portionis rotatable with respect to the rotation axisand is received in and extends through the through holes,formed in the axle memberand in the support member, respectively. The second drive shaft portionis supported on the axle memberby means of a bearing.

The epicyclic wheel end reduction driveincludes a sun gear, a planetary carrierhaving a plurality of planet gearsrotatably mounted thereon, and an outer ring gearwhich is fixedly mounted on the support memberof the support assembly. In other words, in the embodiments depicted in the figures, the support memberis configured as a ring gear carrier. It is understood that in alternative embodiments not explicitly depicted here, the support membermay possibly be connected to or support another element of a wheel end reduction drive or of an epicyclic wheel end reduction drive such as a planetary carrier, for example.

Further details of some of the elements of the epicyclic wheel end reduction drivecan be observed in. The sun gearis fixedly mounted on an axial end of the second drive shaft portionsee. A rotation axis of the sun gearcoincides with the rotation axis. The planetary carrieris configured as a cylindrical hub case fixedly connected to the wheel hubvia axially extending bolts. A symmetry axis of the cylindrical hub case forming the planetary carriercoincides with the rotation axis. The sectional view ofillustrates that the outer ring gearis disposed within the hub case forming the planetary carrier. Or in other words, in a radial direction perpendicular to the rotation axis, the hub case forming the planetary carrierencloses the outer ring gear. As can be observed in, the planet gearsare rotatably mounted on an inner side of an axial end wallof the planetary carrier. The axial end wallof the planetary carrieris arranged perpendicular to the rotation axis.

A symmetry axis of the circular outer ring gearcoincides with the rotation axis. As can be more clearly observed in, the outer ring gearincludes radially inward facing gear teethformed in a radially inner side of the outer ring gear. The gear teethof the outer ring gearextend in parallel to the rotation axis. The radially inward facing gear teethof the outer ring gearare engaged with the radially outward facing gear teethformed at the circular outer rim of the support member, thereby providing a torque-proof connection between the outer ring gearand the support memberwith respect to the rotation axis.

In the axle assemblydepicted in, the planet gearsare in mesh with the sun gearand with the gear teethof the outer ring gear. As the axle assembly, the support memberand the outer ring gearare stationary with respect to the rotation axis, the planetary carrieris fixedly connected to the wheel hub, and the planet gearsare rotatably mounted on the planetary carrier, the rotating drive shafttransmits torque to the wheel hubvia the epicyclic wheel end reduction drive. When the drive shaftdrives the wheel hub, the drive shaft, the sun gear, the planetary carrierand the wheel hubrotate with respect to the rotation axis.

schematically illustrates an electric vehicleincluding two electric motors, two axle assembliesof the type illustrated inand described above, drive wheelsand further wheelsEach of the electric motorsis drivingly engaged or drivingly engageable with one of the two drive wheelsvia one of the axle assemblies. Each of the axle assembliesincludes a drive shaft, an epicyclic wheel end reduction drive, and a support assemblymounted on a vehicle chassis.

are shown approximately to scale.show example configurations with relative positioning of the various components. If shown directly contacting each other, or directly coupled, then such elements may be referred to as directly contacting or directly coupled, respectively, at least in one example. Similarly, elements shown contiguous or adjacent to one another may be contiguous or adjacent to each other, respectively, at least in one example. As an example, components laying in face-sharing contact with each other may be referred to as in face-sharing contact. As another example, elements positioned apart from each other with only a space there-between and no other components may be referred to as such, in at least one example. As yet another example, elements shown above/below one another, at opposite sides to one another, or to the left/right of one another may be referred to as such, relative to one another. Further, as shown in the figures, a topmost element or point of element may be referred to as a “top” of the component and a bottommost element or point of the element may be referred to as a “bottom” of the component, in at least one example. As used herein, top/bottom, upper/lower, above/below, may be relative to a vertical axis of the figures and used to describe positioning of elements of the figures relative to one another. As such, elements shown above other elements are positioned vertically above the other elements, in one example. As yet another example, shapes of the elements depicted within the figures may be referred to as having those shapes (e.g., such as being circular, straight, planar, curved, rounded, chamfered, angled, or the like). Further, elements shown intersecting one another may be referred to as intersecting elements or intersecting one another, in at least one example. Further still, an element shown within another clement or shown outside of another element may be referred as such, in one example.

It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. Moreover, unless explicitly stated to the contrary, the terms “first,” “second,” “third,” and the like are not intended to denote any order, position, quantity, or importance, but rather are used merely as labels to distinguish one element from another. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.

As used herein, the term “approximately” or “substantially” is construed to mean plus or minus five percent of the range unless otherwise specified.

The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.